The genre of epic fantasy, with its origins in patriarchal mythologies, has traditionally been the realm of male protagonists and masculine modes of heroism. Authors of children’s epic fantasy, however, often portray pairings of male and female child protagonists working together in the fight against evil. And yet, despite the inclusion of female protagonists in many epic fantasies for children, patriarchal values dominate the genre, as aggression, physical prowess, rational detachment, and action define the hero. Through the lens of post-structural feminist theory, this study—spanning twelve texts, seven main characters, and 130 years of literary history—examines the female child protagonist and the intersection of girlhood and heroism as depicted in the epic fantasies of George MacDonald, C.S. Lewis, and Philip Pullman.